Induction heating apparatus



Oct. 11, 1949. p MOLLQY INDUCTION HEATING APPARATUS Filed Sept. 6, 1945 2 Sheets-Sheet 1 I l l l l l 7 ll INVENTOR. Pa'lrz'c ZZZ Molly BY W I n f M ATTQO RN E Ys Oct. 11, 1949. p. F. 'MOLLOY 2,484,238

INDUCTION HEATING APPARATUS Filed Sept. e, 1945 2 Sheets-Shet z INVENTOR.

PaZrz'ckFMoZZqy W, (1J1 AM ATTORNEYS Patented Oct. 11, 1949 0F 2,,4s4,2ss

INDUCTION H'EATINGAPPARATUS Patrick-Fl Molloy,. Long Island, Y assignorta Induction: Heating Corp New York, N. Y a. corporation of New York Application September 6, 1945, SerialNo. 614,650

2 Claims. 1..

Thisinvention relates to induction heating apparatus and; more particularly. to such apparatus for concurrently heating a plurality of parts or assemblies ot parts which are. to be brazed, hardened' or otherwi'setreated.

Animportan-t feature of the invention resides in the provision of a two section inductor in which the twosections are relatively movable in a'novel hinged relationship. When the sections of the inductor are in open position, acoording to one example of the invention, the compo nent parts of a work assembly are placed in assembled relation upon each of a plurality of work holders. The sections of the inductor are then swung to closed position and, in this position, each of the assemblies is received in an opening or'passage formed in the inductor wherein a strong-electromagnetiefield is established during passage of current through the inductor, this electromagnetic field being effective toheat and b'raze together the component parts of the respective'workassemblies, as well as toharden the outer surfaces of the parts if desired.

After the heating is completed, a spray of Water orv other quenching medium may be directed against'each work assembly to thereby cool and harden the respective parts thereof The inductor sections may thenbe moved to open position and the assemblies removed from the inductor.

Various other objects, features and advantages of the invention will clearly appear from the detailed description given below taken in connectionwith the accompanying drawings forming a. part. of the specification and illustrating, by way of. example, preferred forms of apparatus which. may. be used in carrying out the invention. The invention resides in such novel fea. tures, arrangements, and. combinations oi parts as may be shown and described in connection with the apparatus herein disclosed.

In the drawings;

Fig. 1 is a top plan view, partiallyin section, of the apparatus of the present invention;

Fig. 2 is a front elevationei view of the app ratus shown in Fig. 1;

Fig. 3' is a front view of the inductor with the inductor sections in open position;

&-..4is: an enlarged-end elevational view, partially in section, of the apparatus shown inFig. 1;

Fig. 5. is a detailed View showing one of the pivots forthe inductor;

Fig.- 6 is an enlarged end View of the inductor with. the parts: inthe position shown in Fig. 3; and.

Fig; '7 isza perspective view of a modified form ofincl-uctor.

Referring to the drawings in detail and particularlyttoli'igs. Iv and 2, the apparatusas shown comprises an inductor I having: alower stationary section: tllsfixed to abase II and an. upper movable. section It. which may be pivotally mounted on'the; lower section: ID. The stationary section Illzmay comprise a pair of longitudinally alisned conductors I3 and M, the facing ends of which are; separated by an airgap as at I5, such ends being connected, in a known manner, to the re-v specltive; secondary terminals (not shown) ofv a suitable high frequency transformer by a pair of spaced. conductors. I 6, I6; provided with attaching lugs. or terminals Hi and l l, respectively. Theconductors t6; h'i'maybe secured to; an insulating strip: H3; asby screws I9 to maintain said conductors.in-closely-spaced parallel relationship... Eachof the. conductors I3: and It may be secured ton-supporting post 26', Figs. 3: and 4, which, in turn, may: be secured to the base II in any suitable mannerso that the stationary section II] is rigidly mounted upon the. base I' I The movable section IZ 'of: the inductor may be hinged at each end thereofto the stationary section llllisoethattheparts-may be moved to the open position shown in Figs. 3 and ti to allow the work to be assembled within the inductor in the manner hereinafter described. The movable section is thenswu-ng totheclosed position shown in Figs. 1and'2 before the heating operation starts. To provide pi voting means for the movable section I 2', the same maybe shaped to form downwardly extendingprojectionsib at each end thereof, Fig. 23,v andl-ugs 26 Fig. '1, are formed on the lower portions oi:' the projections 25, said lugs being in alignment with lugs 21* formed on the adjacent conductor I4; Referring to Figs. 1 and 5, hinge pins 2'8'extend'throughsuitable aligned passages in thelugs Zfi and 21, the passages in lugs it being internally threaded to receive a threaded portion of the associated hinge pin 28 which may be held inthe position shown in Fig. 5' by a suitable set screw as at 29:.

Swingingmovement of the upper section I2 in a counter-clockwise direction, Fig. 4, may be limited by stop members 30 and 33'; Fig. 1, which are mounted, respectively, at the ends of conductors I S and t4. Swinging movement of the upper secti'on I 2 ina clockwise direction, Fig. 4, may celimi'ted lay-engagement of said upper section witli the insulationstri-p- I'll. A handle may be provided as: at 3| to facilitate moving the upper section'I-Zwith respectto thestationary section III.

The movable section [2 may be shaped to form a plurality of openings 35, Fig. 2, hereinafter refered to as heating zones which, in the example shown, are of rectangular cross section. Each of these heating zones is adapted to receive and inductively heat a work assembly as will be hereinafter described. When a high frequency alternating voltage is applied to the lugs l1, l1 and the movable section I2 is in closed position, current flows through the inductor to thereby establish an intense high frequency electromagnetic field within the heating zones. In order to establish a uniform field intensity in each of the heating zones, the movable section 12 may be shaped to form a narrow vertically extending slot 36 at each end of the inductor. The slots 36 serve to space the regions of increased field strength at the respective opposite ends of the inductor away from the end heating zones so that the field strength is substantially the same in each zone. Excessive induction between opposite portions of the inductor is prevented by making the slots 36 quite narrow and by forming the upper section l2 so that, except for the area defined by the heating zones 35, the lower surfaces l2 are quite close to the conductors l3 and [4 when the inductor is in closed position. As shown, there is a group of three heating zones 35 at each side of the inductor and these disposed symmetrically with respect to the center of the inductor.

The necessary cooling system for the inductor may comprise an inlet pipe 38, Fig. 1 which communicates with one end of a passage 39 extending through the adjacent conductor 16 and the conductor [3. The other end of the passage 39 2.

may be connected by a flexible hose 40 to one end of a passage 4| which extends through the upper section l2. The other end of the passage 4| may be connected by a flexible hose 42 to one end of a passage 43 which extends through the conductor I4 and the adjacent conductor IE to an outlet pipe 44. Accordingly, it will be apparent that a continuous stream of cooling fluid may be passed through the inductor to prevent undesirable overheating thereof.

In accordance with the invention, a work holder H may be disposed adjacent each of the openings 35. Each of these work holders is adapted to receive a plurality of parts which are to be brazed or soldered together to form an assembly. In the example shown, the work holder is adapted to receive a jaw face and a plier shank and hold these parts in proper assembled relation during the heating operation but it is to be understood that the invention is not to be restricted to the particular example shown, as work holders may be devised for holding the component parts of various other types of assemblies.

Referring to Fig. 4, each work holder may comprise a support 45 suitably secured to the base H. A pair of side pieces 46 and 41, Fig. l, are formed at the top of this support and a pin 46 extends through the side piece 46 into the space between the side pieces. With the movable section l2 in the dotted line position shown in Fig. 4, a plier shank 48 may be inserted into the space between the side pieces 46 and 41, the butt of such shank passing through a recessed portion 41 formed in the side piece 41. The shank is initially placed so that the pin 45' extends into a passa e 48 formed in the shank. The latter is then released whereupon it drops to the position shown in Fig. 4, and engages a flange 49 formed at the top of the support 45. In this manner, the plier shank is securely held in the full line position shown in Fig. 4 by the pin 46' and the flange 4B. A support 5| mounted on the base ll may carry a. yoke member 52 having a forked end portion 53 which is of the proper size to receive a jaw face 54 and support this part in proper assembled position with respect to the plier shank 48. It will be noted that the fork 53 is sufficiently large that it does not interfere when the plier shank is dropped into position in the manner hereinbefore described. It will be apparent that the jaw face 54 and the portion of the plier shank in contact therewith are disposed within the adjacent heating zone 35 when the movable section I! is swung to closed position.

Quenching apparatus Q is provided to direct a stream of quenching fluid upon the assembly after the brazing operation is completed. This apparatus may include a conduit 56 supported by the base I l and extending longitudinally thereof. This conduit may be supplied with quenching fluid from any suitable source, not shown. A plurality of pipes 51, one for each work holder, branch from the conduit 56 and each pipe is adapted to direct a jet quenching fluid upon the adjacent jaw face-plier shank assembly when it is supported by the work holder H in the position shown in Fig. 4.

The operation may be briefly summarized as follows. After the assembly of parts to be heated is arranged as above described, in the work holder, a brazing or soldering compound and a suitable fiux are placed on the assembly adjacent the joint between the plier shank and the jaw face. Thereupon, the upper section I2 is moved to the closed position, cooling fluid being circulated through the inductor in the manner previously described. A suitable high frequency current is applied to the lugs H, H, with the result that a very intense electromagnetic field is established within each of the heating zones 35 and the jaw face-plier shank assembly is inductively heated to the desired temperature in a very short period of time so that the parts of the assembly are rapidly brazed or soldered together. As soon as the brazing operation is completed, the current is turned off and quenching fluid is passed through the conduit 56 and pipes 5'! so that a jet of fluid is sprayed upon each of the brazed assemblies to cool and harden the same. Thereupon, the upper section I 2 is moved to open position and the assemblies are removed.

It will be understood that the parts of the respective assemblies are very accurately fitted together as the parts are held in the exact position desired by the respective work holders. Moreover, since the magnetic field is of substantially the same strength in each of the heating zones 35 very uniform results are obtained which are easily reproducible by controlling the heating time. The speed of operation is greatly increased by providing the movable upper section I2 since this allows adequate working space for assembling the parts in proper position inside the inductor. From Figs. 3, 4 and 6, it will be apparent that the position of the hinge axis for section I2 is to the rear of section !0 and in a position such that the work holders are freely accessible and unobstructed when the section I2 is swung back.

It will be apparent that the shape of the heating zones may be varied, if desired, so that the inductor may be used for heating other types of assemblies. Thus, for example, the heating zones may be of circular cross-section, as shown in Fig. '7, and each heating zone may be defined by facing semi-circular recesses formed, respectively, int.

the movable and stationary sections of the inductor. Whether the work piece openings are formed entirely by recesses in one of the sections or by recesses in both sections, it will be apparent that the adjacent faces of the sections a referred to in the appended claims are shaped to form the desired work piece openings.

While the invention has been described with respect to present preferred embodiments which have given satisfactory results, and certain modifications have been referred to, it will be understood by those skilled in the art, after understanding the invention, that various other changes and modifications may be made without departing from the spirit and scope of the invention and it is intended, therefore, in the appended claims to cover all such changes and modifications,

What is claimed as new and desired to be secured by Letters Patent, is:

1. In high frequency induction heating apparatus, an inductor comprising an elongated stationary inductor portion, another elongated inductor portion hingedly connected at its ends respectively to the ends of said stationary portion, said stationary portion being formed with a transverse gap intermediate its ends, means for connecting the terminals of a source of high frequency current to opposite sides of said gap, the normally adjacent longitudinal faces of said two portions being shaped to form transverse openings in the inductor at each side of said gap for receiving work pieces, such openings being interconnected by narrow slots whereby a current path surrounding said openings is provided to extend from one side of said gap along one part of said stationary portion through a hinge connection to the other inductor portion, thence to and through the other hinge connection and the other part of the stationary portion back to the gap, the axis of said hinge connections being generally parallel to the inductor portions and said axis being positioned and said portions being so constructed and arranged as to permit the hinged inductor por tion to be swung to freely expose said adjacent longitudinal faces to facilitate insertion of work pieces in said openings, and to permit the hinged portion to be swung back to bring such faces at the openings into closely spaced coupling with the work.

2. In high frequency induction heating apparatus, an inductor comprising a pair of elongated inductor portions normally positioned to extend horizontally in closely spaced relation one above the other, the adjacent faces thereof being shaped to form a plurality of transverse openings therebetween for receiving work pieces, pivotal connection means interconnecting said portions adjacent their ends, the axis of said pivotal means being generally parallel to the inductor portions and oiTset rearwardly of the lower portion to permit the upper portion to be swung back with respect to the lower portion to freely expose said adjacent faces at the openings to facilitate insertion of work pieces, and means for connecting said portions in series with a source of high frequency current,

PATRICK F. MOLLOY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,776,607 Younghusband Sept. 23, 1930 1,813,591 Ulrey July 7, 1931 1,864,076 Legg June 21, 1932 2,170,130 Denneen et al. Aug. 22, 1939 2,180,038 Denneen et a1 Nov. 14, 1939 2,271,916 Denneen et a] Feb. 3, 1942 2,280,689 Denneen et al Apr. 21, 1942 2,308,788 Somes Jan. 19, 1948 2,402,508 Strickland June 18, 1946 2,404,987 Rudd July 30, 1946 

